It has been known for some time that a nursing bottle may be used by an infant in an upright position by the provision of a drinking tube. The drinking tube of such bottles extends from the nipple end of the bottle axially the length of the bottle to its bottom. However, in many such bottles, for example, those disclosed in U.S. Pat. Nos. 2,655,279; 2,868,203; 2,877,917; 2,984,377; 3,346,133; 3,441,160; and 4,557,392, the drinking tube is sufficiently rigid that the innermost end of the drinking tube remains close to the bottom of the bottle so that liquid cannot be drawn from the tube when the bottle is inverted and can allow the infant to draw in air, causing colic.
U.S. Pat. No. 3,059,797 discloses an infant nursing bottle which allows liquid to be drawn through the nipple whether the bottle is held up or inverted. However, it uses a complicated design with plural float valves which would be expensive to manufacture and require careful maintenance and cleaning.
U.S. Pat. No. 3,044,650 discloses a nursing bottle having a flexible tube which will fold upon itself when the bottle is inverted. Unfortunately, due to the relatively narrow bore of conventional nursing bottles, such collapsible drinking tubes must be so collapsible to fold upon themselves that they inevitably buckle and crease. U.S. Pat. No. 3,547,296 thought to avoid such a problem by providing a reinforcing spring to widen the bend of the drinking tube to prevent collapse of the tube wall. However, such a device is relatively complicated to manufacture and the coil spring provided would be a source of cleaning and maintenance problems.
Other drinking devices would also benefit from the ability to supply liquid to a drinker regardless of the orientation of the device. For example, the present invention would be quite useful in the medical/health care field for giving liquids to aged individuals, individuals with physical limitations, etc. Also, joggers' or bikers' bottles or the like may or may not be provided with a drinking tube. Some of the limitations of infant nursing bottles can be avoided by making the container portion of the device flexible so that the user can squeeze the container to expel liquid as well as pour or draw liquid with a drinking straw from an upright container. The drawback of such containers is that it is sometimes difficult to control the degree to which the container is squeezed when using the container while exercising. Also such containers are usually so readily flexible that accidental expulsions can occur, sometimes just while handling a full container. Further, once the container is about one-half to two-thirds empty, it is difficult to compress the container sufficiently to expel fluid. Stiff and/or large containers may be too difficult for children and many adults to squeeze at all. If equipped with bendable drinking straws or such straws with springs as disclosed in U.S. Pat. Nos. 3,044,650 or 3,547,296, such drinking devices would still suffer from the same infirmities indicated above for nursing bottles. Since joggers' and bikers' bottles are often used while exercising, stiff walled bottles lacking straws or tubes can be dangerous to use as they may have to be tipped up to disperse liquid and could block the user's vision.
Still other drinking devices include drinking tubes for various other reasons. For example, U.S. Pat. Nos. 4,448,316, 4,735,329, 4,892,187 and 4,923,083 all disclose containers with pop-out drinking tubes which permit easy access to the protruding end of the tube when the container is opened. U.S. Pat. Nos. 4,735,329 and 4,923,083 both disclose coiled, resiliently springy drinking tubes. U.S. Pat. No. 4,892,187 discloses a buoyant or float-equipped flexible drinking tube. U.S. Pat. No. 4,448,316 discloses the use of a spring member to bias flexible drinking tube from the mouth of the container. Each of these devices suffers the drawbacks of conventional drinking straws when used with containers in that each device can only be used to draw fluid from the container when the container is held in an upright orientation.
None of the aforesaid references discloses drinking devices which are optimally suited for dispensing liquid in virtually any orientation of the device.